A six-layers of Jerusalem Frequency Selective Surface (JC FSS) structure is used to demonstrate the GEMS performance to handle the complex structures. Due to the slight shift of the fine structures, the FDTD mesh cannot catch up with all the fine features in the FSS screen. Carefully design the mesh and let the mesh reach the best approximation.

Since the JC FSS structure and feed horn are symmetric about XoZ and YoZ planes, we can reduce the problem size to the quarter and simulation and memory requirement will be reduced accordingly. To reduce the domain size, we need to use the PEC or PMC boundaries to truncate the computational domain in the X and Y directions.

The selection of PEC and PMC depends on the polarization of excitation field. For instance, if the palliation is EX, the PEC boundary should used in the X direction and the PMC boundary should be used in the Y direction.